<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			#unite{
				width: 100%;
				height: 100px;
			}
			#smile span{
				height: 50px;
				width: 50px;
				position: absolute;
				background: mistyrose;
				animation: smile 5s infinite;
			}
			@keyframes smile{
				0%{
					transform:translateY(0) ;
				}
				100%{
					transform: translateY(100px);
				}
			}
		</style>
	</head>
	<body>
		<div id="unite">
			<div id="smile">
				<span></span>
			</div>
		</div>
	</body>
</html>
